The present invention relates generally to a cladding system for the concealed fixing of roofing or other cladding sheets and to a clip and cladding sheet for use in such a system.
Throughout the specification, the invention is described with reference to the orientation for use in roof cladding where the plane of the sheets is generally horizontal. This, however, should not be construed as limiting the invention to that orientation, as the cladding may be laid in other orientations. Accordingly, references to a particular orientation is to be construed to encompass these other orientations.
Cladding sheets for concealed fixing have a plurality of longitudinal, re-entrant ribs, with pan sections between the ribs. The edges of the sheets are adapted for interengagement with the adjacent sheets, so that an end rib of one sheet fits over the end portion of the adjacent sheet.
The sheets are typically secured to the roof structure by elongated clips which secure the trailing edge end portion of the previously laid sheet and the end rib and intermediate ribs of the sheet to be laid. The clip has retaining formations spaced along the length thereof to coincide with the rib spacing. An endmost retaining formation of the clip is engaged with the trailing edge portion of the previously laid sheet, with the remainder of the clip extending in the direction of progress, and is fixed to the roof structure. The next sheet is then pressed onto the clip so that the leading edge rib and intermediate ribs are engaged with the retaining formations and the leading edge rib also locks over the trailing edge portion of the previous sheet.
The prior art clips are formed as a strap, which is folded to form a series of humps. The humps have detents for engagement with re-entrant portions of the ribs of the sheet.